Kilburn stepped out of the elevator onto the ninth floor, the respirology ward. After another busy night on call, punctuated by two more drunken phone calls from Kyra, Kilburn felt spent. But the ward’s purposeful buzz energized him. The bright corridor bustled with people and outfits. Gowned patients pushed poles bearing IV bags up and down the hallway. Staff wearing scrubs, short and long white coats, and such a rainbow array of hospital uniforms rushed by that Kilburn had trouble distinguishing physicians from cleaners.

Reaching the nursing station, Kilburn pulled up a chair at the computer in the semiprivate nook at the back. On the temperamental electronic records system, he pulled up Thomas Mallek’s chart. After scanning the admission history and lab work, Kilburn viewed the chest x-ray online. He studied the image, adjusting the contrast and brightness and zooming in and out on various zones of the chest. With a dense white patch occupying the normal blackness of the lung’s right bases, he decided the x-ray was classic for an advanced lobar pneumonia.

Kilburn tapped the mouse, and the sputum culture report appeared. The preliminary results read “gram-positive cocci in chains.” Must be invasive group-A strep, he thought. The antibiotic sensitivities were listed as “pending,” but he knew that G.A.S. had a good response to most antibiotics, which made the patient’s stormy hospital course even harder to explain.

He rose from the desk and walked halfway down the hall to Mallek’s private room. Stepping inside, the first person Kilburn saw was a woman sitting in the bedside chair and clutching the patient’s hand in hers. Her red eyes and drawn face suggested she hadn’t slept in days. Despite her fatigue and lack of makeup, the fortyish woman was still attractive with short brunette hair and large hazel eyes.

Kilbum turned his attention to the patient. Thomas Mallek lay propped up on the bed against a pillow with a sheet drawn around his waist. Much of his face was covered by a clear plastic oxygen mask known as a Star Wars mask because of its similarity in shape to the one worn by Darth Vader. From the mask alone, Kilburn appreciated the severity of the pneumonia. If the Star Wars mask failed to help, a ventilator and life-support system would soon follow. His eyes were drawn to the patient’s exposed chest where the gown had fallen open. Mallek had a lean runner’s chest, but he was breathing far more quickly than expected. The muscles between his ribs sucked in with each breath. Without raising his stethoscope, Kilburn recognized the signs of severe respiratory distress.

He approached the patient with a smile. “Mr. Mallek, I’m Graham Kilburn, an infectious-disease specialist.”